Yes, larger solar panels can charge faster under equivalent conditions due to higher wattage output. With the growing interest in renewable energy, many people are curious about the efficiency and speed of solar charging. Whether you're powering a small gadget or storing energy for your home, knowing the charging time. To determine whether adding more solar panels will charge a battery faster, it's essential to understand how solar panels generate electricity. A 50-watt panel may take longer. Formula: Charging Time (h) ≈ (Battery Ah × V × (Target SOC / 100)) ÷ (Panel W × (Eff% / 100)). There are many different variables that will affect the ultimate result, such as the size of the battery, the efficiency of the panel, the number of hours in a day of sunlight, etc. In this guide, we'll walk you through.